Due to the willingness of companies to be highly responsive to varying customer demands, the flexibility of warehouse materials handling technology has become very significance. Fast and efficient storage and retrieval of items from their rack locations is important for high throughput operations. Automated Storage and Retrieval Systems (AS/RSs) are widely used in modern distribution centers. Due to the relative inflexibility of the physical layout of a warehouse, it is very important to design a warehouse right the first time. This book will provide an insight for warehouse practitioners, on how to design and operate their facilities as well as present the different types of AS/RSs.